Inorganic mercury pharmacokinetics in man: a hybrid model.

A four-compartment model is presented that simulates inorganic mercury [Hg(II)] pharmacokinetics in blood, tissue, and excreta over a 70-day period. Simulations are validated against data collected from five human subjects, and previously analyzed.In the model, two compartments simulate Hg(II) in blood: one for mobile-Hg(II) and the other for immobile-Hg(II). Two corresponding compartments simulate Hg(II) in tissue. Mobile-Hg(II) represents Hg(II) available for transport across cell membranes. Immobile-Hg(II) represents Hg(II) that is not easily transported.Following dosing, blood total-Hg(II) droped rapidly in all subjects. Blood mobile-Hg(II) also droped rapidly with a concomitant rise in blood immobile-Hg(II). For four subjects, immobile-Hg(II) became the dominant Hg(II) species in blood by day 4. For subject five, mobile-Hg(II) remained dominant in blood for the study duration.Tissue mobile-Hg(II) declined rapidly for four of the subjects, with a simultaneous rapid rise in tissue immobile-Hg(II). In subject 5, tissue mobile-Hg(II) declined linearly, and immobile-Hg(II) accumulated slowly in tissue. For all subjects, tissue mobile-Hg(II) is the primary source of fecal Hg(II). The major source for Hg(II) excreted into the urine is immobile-Hg(II) from tissue.